Presently, complex duct cleaning systems include vacuum pressurized pneumatic lines, pressurized fluid spraying lines and pneumatically operated whirling brushes. The fluid or air under pressure and the whirling brushes loosen dust, dirt and grime, and a vacuum line is supposed to pick up the residue. So-called advances in these systems have included making them more complex with additional optional equipment.
German Patent 162130 discloses a flue cleaner having a rectangular metal frame with an expansible rubber outer surface for scraping against the rectangular sides of a flue.
U.S. Pat. No. 856,063 discloses an expansible pipe cleaner having a rubber bladder that may be flattened and made to a larger diameter by screwing a nut along a central rod to expand the diameter of the bladder. The patent also discloses a ribbed outer surface for the bladder.
U.S. Pat. No. 5,285,806 discloses an inflation bag which when used with a retaining rod positioned diametrically across a pipe line in conjunction with a high pressure source of compressed gas will block a pipeline from fluid flow therethrough.
A need has developed for an improved simplified apparatus for cleaning heating, ventilating and air conditioning ducts.
Additionally, a need has developed for providing an improved simplified apparatus for cleaning ducts which is capable of cleaning both rectangular and circular HVAC ducts.